At present, OLED display devices serving as active light emitting devices receive more and more attention, and the manufacturing technology of the OLED display devices is gradually mature. Generally, an OLED pixel is mainly manufactured through the following three steps: forming a TFT (thin film transistor) circuit and an OLED anode on an OLED substrate; forming an OLED light emitting layer; and depositing a film to form an OLED cathode, wherein the OLED light emitting layer is formed generally by evaporation, but the evaporation has the following problems:
1. because the sublimation temperature of an OLED light emitting material is very high, a mask is easily deformed during evaporation, and the fineness of a device structure cannot reach the standard;
2. large-area production cannot be realized, otherwise, the center of the mask droops;
3. non-uniformity of film thickness is easily caused by non-uniform evaporation;
4. if the OLED light emitting layer is formed by printing, the problems of non-uniformity display, low light emitting efficiency and the like are caused due to the characteristic of material whose granules are thick in the middle and thin in the edge; and
5. if the OLED light emitting layer is formed with a silk-screen printing process, the problems that displaying is non-uniform and the light emitting layer is thick in the middle and thin in the edge exist likewise.
Moreover, the above process still has the following problems which cannot be solved at present:
1. R(red)G(green)B(blue) full-color film formation cannot be realized, as the OLED light emitting layer is forbidden to be exposed and cannot contact H2O or O2 and thus cannot be etched;
2. in order to achieve a full-color display effect, a blended color filter needs to be added, but in this case, a display device is very thick in overall size, complex in process and low in light utilization rate; and
3. valuable OLED light emitting materials are wasted.